Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/10—Esters; Ether-esters
  • C08K5/101—Esters; Ether-esters of monocarboxylic acids
  • C08K5/103—Esters; Ether-esters of monocarboxylic acids with polyalcohols
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/16—Ethylene-propylene or ethylene-propylene-diene copolymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/04—Carbon
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2312/00—Crosslinking

Definitions

• the present invention relates to an EPDM composition. More specifically, the present invention relates to an EPDM composition used as a molding material for automobile anti-vibration rubber and the like.
• Anti-vibration rubber for automobiles is essential for preventing vibrations and noise generated mainly from the engine and vibrations and noise received from the road surface from being transmitted into the interior of the car.
• the heat-resistant environment near the engine room or around the exhaust pipe has become more severe than before.
• anti-vibration rubber When anti-vibration rubber deteriorates due to heat, it not only reduces its anti-vibration and damping functions due to an increase in the spring constant or elastic modulus, but also causes a deterioration in durability due to a decrease in strength and elongation. becomes. Therefore, anti-vibration rubber is required to have high heat resistance in order to maintain the functionality of products to which it is applied.
• EPDM is a well-balanced polymer that has both high heat resistance and excellent low-temperature properties, and is generally used as a vibration-proof rubber for automobiles by using EPDM as a base polymer and blending technology with other fillers and plasticizers. Efforts are being made to improve the heat resistance and low-temperature properties of
• EPDM ethylene glycol dimethacrylate copolymer
• Patent Document 1 ⁇ -olefin oligomers
• Patent Document 2 blending aliphatic dibasic acid esters
• Products containing group dibasic acid esters have excellent low-temperature properties, but are susceptible to thermal deterioration due to abstraction of ⁇ -hydrogen atoms derived from alcohol by the oxygen atoms of carbonyl groups, and the heat resistance of rubber materials deteriorates. It tends to significantly impair sexuality.
• ⁇ -olefin oligomers are blended, although the balance between low temperature resistance and heat resistance is excellent, recent demands for even higher standards require further improvement in both of these properties.
• An object of the present invention is to provide an EPDM composition that provides a rubber with an excellent balance of low-temperature resistance and heat resistance, such as vibration-isolating rubber for use in damping products for crankshafts, propeller shafts, and various mounting products. be.
• the object of the present invention is to provide a rubber composition in which carbon black, a plasticizer, and a crosslinking agent are blended into an ethylene-propylene-diene ternary copolymer rubber, in which the plasticizer is a reaction product of a neopentyl polyol and a monocarboxylic acid.
• the plasticizer is a reaction product of a neopentyl polyol and a monocarboxylic acid.
• the EPDM composition according to the present invention does not impair kneadability or processability, and the resulting crosslinked product is comparable in hardness change after a heat aging test to the same level as when the same amount of ⁇ -olefin oligomer is blended. Moreover, it has an excellent effect that is significantly improved compared to the case where an aliphatic dibasic acid ester is blended.
• EPDM ethylene-propylene-diene tertiary copolymer rubber
• furnace black which is generally used as a reinforcing agent, can be used, preferably one having a nitrogen adsorption specific surface area of 20 to 240 m 2 /g and a DBP oil absorption of 40 to 180 ml/100 g.
• HAF carbon black, FEF carbon black, etc. are used.
• Carbon black is used in the EPDM composition in a proportion of about 20 to 40% by weight, preferably about 25 to 40% by weight. If carbon black is used in a proportion smaller than this, the reinforcing properties will be reduced and it will be difficult to satisfy the basic physical properties of rubber materials. This is not preferable because it may adversely affect the physical properties of the material.
• the plasticizer is a polyol ester composed of a neopentyl polyol and a monocarboxylic acid, preferably a trivalent neopentyl polyol such as trimethylolpropane and a carbon atom number of 5 to 15, more preferably 5 to 15 carbon atoms.
• the polyol ester which is the reaction product of 12 linear monocarboxylic acids, is present in the EPDM composition in an amount of about 5 to 22 weight percent (e.g., 8 to 40 parts by weight per 100 parts of EPDM), preferably about 5 to 19 weight percent. %.
• Polyol esters which are composed of neopentyl polyols and monocarboxylic acids, do not have alcohol-derived ⁇ -hydrogen atoms in their molecular structure, so they are resistant to thermal deterioration and have excellent heat resistance and low temperature properties.
• commercial products such as Nippon Oil & Fats Products Unistar H-327R, H-334R, etc. can be used as they are.
• the composition that is the basis for calculating the weight proportion of plasticizer is ethylene-propylene-diene ternary copolymer rubber, carbon black, plasticizer, crosslinking agent, acid acceptor, lubricant, anti-aging agent, etc. Even if other compounding agents are included, they are not included in the total weight of the composition, which is the basis for calculating the weight proportion of plasticizers, etc. Not possible. If the amount of polyol ester in the composition is less than 5% by weight, the effect of improving low temperature properties will be small, while if it exceeds 22% by weight, the productivity and processability of the rubber material will deteriorate, and the polyol will be removed from the crosslinked product. Ester begins to precipitate.
• organic peroxide crosslinking agent for example, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3, or other organic peroxides commonly used in the crosslinking of EPDM, are used in an amount of about 0.5 to 2.5% by weight, preferably about 1.0 to 1.8% by weight, in the EPDM composition.
• organic peroxide crosslinking agents a number of compounds such as triallylisocyanunate, triallylcyanurate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, N,N′-m-phenylenemaleimide, etc. are commonly used. It is preferable to use a functional unsaturated compound, 1,2-polybutadiene, etc. in combination, and these co-crosslinking agents are used in a proportion of about 1.0 to 5.0 parts by weight per 100 parts by weight of EPDM.
• divalent metal oxides or hydroxides, acid acceptors such as hydrotalcite, lubricants such as stearic acid, and commonly used anti-aging agents for EPDM each have a concentration of about 3.0 to 5.0 per 100 parts by weight of EPDM. Parts by weight, approximately 0.5 to 3.0 parts by weight, approximately 0.5 to 3.0 parts by weight.
• various compounding agents that have been widely used in the past may be optionally added to the EPDM composition containing the above-mentioned components as essential components within the range that does not impair the purpose of the present invention. can.
• the preparation of the EPDM composition is carried out by kneading using a kneader, rolls, etc., and the kneaded product is generally crosslinked into a desired shape by press vulcanization at about 170 to 190 ° C. for about 2 to 6 minutes, and Further, if necessary, oven vulcanization (secondary crosslinking) is performed at about 150 to 180°C for about 1 to 5 hours.
• Example 1 EPDM (JSR product EP22) 100 parts by weight HAF carbon black 56.6 Polyol ester plasticizer 24.4 ⁇ (NOF Unistar H-327R) [Plasticizer amount 12.6% by weight] Zinc oxide 5 Stearic acid 0.5 ⁇ Anti-aging agent 0.5 ⁇ Co-crosslinking agent 5.0 ⁇ Crosslinking agent 2.3 ⁇ After kneading each of the above components other than the crosslinking agent in an internal kneading machine, the components were transferred to an open roll, the crosslinking agent was added thereto, and after further kneading, press vulcanization was performed at 180°C for 6 minutes and 150°C Oven vulcanization was performed at °C for 5 hours to obtain a crosslinked product.
• JSR product EP22 100 parts by weight HAF carbon black 56.6 Polyol ester plasticizer 24.4 ⁇ (NOF Unistar H-327R) [Plasticizer amount 12.6% by weight] Zinc oxide 5 Stearic acid 0.5
• Example 2 In Example 1, the amount of plasticizer was changed to 9.8 parts by weight (5.5% by weight).
• Example 3 In Example 1, the amount of plasticizer was changed to 39.1 parts by weight (18.7% by weight).
• Example 2 Comparative Example 2 In Example 1, the amount of plasticizer was changed to 5.2 parts by weight (3.0% by weight).
• Comparative example 3 In Example 1, the amount of plasticizer was changed to 58.6 parts by weight (25.6% by weight).
• Comparative example 4 In Example 1, the amount of plasticizer was changed to 87.9 parts by weight (34.1% by weight).
• Example 4 In Example 1, the same amount (25 parts by weight; 12.6% by weight) of polyol ester (Nippon Oil Products Unistar H-334R) was used as a plasticizer.
• Example 5 In Example 4, the amount of plasticizer was changed to 9.8 parts by weight (5.5% by weight).
• Example 6 In Example 4, the amount of plasticizer was changed to 39.1 parts by weight (18.7% by weight).
• Comparative example 5 In Example 4, the amount of plasticizer was changed to 58.6 parts by weight (25.6% by weight).
• Comparative example 6 In Example 4, the amount of plasticizer was changed to 87.9 parts by weight (34.1% by weight).
• Comparative example 7 In Example 1, the same amount (24.4 parts by weight; 12.6% by weight) of poly ⁇ -olefin (Durasyn 170, manufactured by INEOS Oligomers) was used as a plasticizer.
• Comparative example 8 In Comparative Example 7, the amount of plasticizer was changed to 9.8 parts by weight (5.5% by weight).
• Comparative example 9 In Comparative Example 7, the amount of plasticizer was changed to 39.1 parts by weight (18.7% by weight).
• Comparative example 10 In Example 1, the same amount (24.4 parts by weight; 12.6% by weight) of poly ⁇ -olefin (Durasyn 164, manufactured by INEOS Oligomers) was used as a plasticizer.
• Comparative example 11 In Example 1, the same amount (24.4 parts by weight; 12.6% by weight) of dioctyl sebacate (DOS, manufactured by Taoka Chemical Industries) was used as a plasticizer.
• DOS dioctyl sebacate
• Comparative example 12 In Example 1, the same amount (24.4 parts by weight; 12.6% by weight) of diisodecyl adipate (DIDA, manufactured by Taoka Chemical Industries) was used as a plasticizer.
• DIDA diisodecyl adipate
• Comparative example 13 In Example 1, the same amount (24.4 parts by weight; 12.6% by weight) of paraffinic process oil (Idemitsu Kosan product Diana Process Oil PW-90) was used as a plasticizer.
• paraffinic process oil Idemitsu Kosan product Diana Process Oil PW-90
• Comparative example 14 In Example 1, the same amount (24.4 parts by weight; 12.6% by weight) of paraffinic process oil (Idemitsu Kosan product Diana Process Oil PW-32) was used as a plasticizer.
• paraffinic process oil Idemitsu Kosan product Diana Process Oil PW-32
• the crosslinked product of the EPDM composition of the present invention has an excellent balance of low-temperature properties and heat resistance, so it can be used as anti-vibration rubber for automobiles used in harsh thermal environments or cold regions, such as control for crankshafts and propeller shafts. Effectively used as a molding material for vibration products and various mounting products.

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• Chemical & Material Sciences (AREA)
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• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
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• Compositions Of Macromolecular Compounds (AREA)

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• 2023
  • 2023-09-19 JP JP2024548255A patent/JP7635470B2/ja active Active
  • 2023-09-19 CN CN202380053127.7A patent/CN119546699B/zh active Active
  • 2023-09-19 WO PCT/JP2023/033936 patent/WO2024063052A1/ja not_active Ceased
  • 2023-09-19 US US18/994,244 patent/US20260049200A1/en active Pending
  • 2023-09-19 EP EP23868173.8A patent/EP4592346A1/en active Pending

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